System of control



Dec. 7, 1926. l

E. w. SEEGER SYSTEM OF CONTRO L Filed March 1926 lNVmToR:

ATTORNEY Patented Dec. 7, 1926.

UNITED STATES PATENT OFFICE.

EDWIN W. SEEGER, OF SOUTH MILWAUKEE, WISCONSIN, ASSIGNORTO THE CUTLER- HAMHEB MFG. (30., F MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

SYSTEM OF CONTROL.

Application filed. March 22, 1926. Serial No. 96,401.

rupting the power connections to the controller during testing, and to also provide for energization of the control elements through the medium of fuses which are normally connected between the controller and said knife switch, but which are capable of being connected ahead of said knife switch for testing purposes. However, in such controllers it has heretofore been possible after testing the control elements to leave such elements in an operative position whereby the controlled motor is likely to be accidently restarted upon reclosure of the knife switch.

The presentiinventionhas among its objects to provide a controller having improved testing means associated therewith which will prevent accidental starting of the con trolled motor after testing of the controller therefor.

Another object is to provide an electromagneti'cally operated motor controller having testing means associated therewith which insuresagainst starting of the controlled motor after testing of the controller except upon return of the elements of the controller to off position.

Various other objects and advantages of the invention will hereinafter appear.

The accompanying drawing diagrammatically illustrates an embodiment of the invention which will now be described. it being understood that the embodiment illustrated is susceptible of modification without departing from the spirit and scope of the'appended claims.

Referring to the drawing. the same illustrates amotor M tobe supplied with current from a direct current circuit. indicated by lines L and L through the medium of a manually operated knife switch 1 and an electro-magnetically operated contactor 2. The speed of the motor M is regulated by l a rheostat 3 having resistance R and R connected in the motor circuit which are adapted to be included and excluded from said circuit in steps by a crosshead 4. Crosshead 4 is operated by a motor m having an armature a. and a series field f, and separately operable double pole switches 5 and 6 are provided for selectively establishing reverse power connections for said motor through the medium of fuses 7 and 8. Fuses 7 and 8 are provided with two sets of clips 9 and 10, the former set being arranged to connect said fuses between knife switch 1 and contactor 2, and the latter being arranged to connect said fuses ahead of said knife switch. If desired a double throw switch may be employed instead of two sets of fuse clips to connect the fuses in the aforesaid manner.

The control means further includes a normally open push button 11 and a normally closed push button 12, said push buttons being arranged in the energizing circuit of the operating winding 2* of contactor 2 and being adapted to control said winding through the medium of a normally closed auxiliary switch 3* associated with rheostat 3. 'As hereinafter set forth, switch 2 in respondmg is adapted to maintain itself in closed position through the medium of auxiliary contacts 2 and the; normally closed push button switch 12 and upon interruption of said maintaining circuit by the latter switch said contactor is adapted to return to off position and can only be reclosed upon return of the rheostat 3 to normal position. Also, the controller includes a normally open push button 13 for controlling the circuit between line U and one of the fuse clips 10.

The function and operation of the aforedescribed controller together with the circuit connections therefor will now be more fullysdescribed. Assuming that the parts are in the position shown in the drawing upon depression of push button 11, the operating, winding 2 of contactor 2 is energized by a circuit extending from line L through fuse 8 by. conductors 14 and 15 throughthe auxiliary switch 3, by conductor 16 through push buttons 11 and 12, by conductor 17 through the operating winding 2* and by conductor 18 through fuse 7 to line L Switch 2 in responding maintains itself in closed position by a circuit extending from line L through fuse 8 by conductors 14 and 19 through the auxiliary contacts 2", by conductor through the normally closed push button 12 and thence through the winding 2 to line L as already traced.

As before stated, the switches 5 and 6 are provided to selectively establish reverse power connections for the crosshead motor m and assuming that switch 5 is depressed said motor is energized by a circuit extending from line L through fuse 8, by conductors 14, 15 and through the lower contacts of switch 5, by conductor 26 to and through the armature a from left to right, by conductors 27 and 24 through the upper contacts of switch 5, by conductor 28 through field f and by conductors 29 and 18 through fuse 9 to line L Upon release of push button 5 and depression of push button 6. the power conections for the crosshead motor on are reversed the same being then established from line L through fuse 8, by conductors 14 and 15 through the upper contacts of switch 6,

'by conductor 27 through the armature a from right to left, by conductors 26 and 30 through the lower contacts of switch 6 and i by conductors 31 and 28 through field f to line L as already traced; It is thus apparent that switches 5 and 6 provide means for effecting operation of the rheostat in opposite directions and in this connection it should be noted that upon movement of said rheostat out of its normal position, auxiliary switch 3' is opened whereby the aforedescribed energizing circuit for switch 2 can only be re-established upon return of the rheostate cross head 4 to normal position.

The fuses 7 and 8 are normally inserted in the clips 9, but for testing purposes the same areremoved from said clips and inserted into clips 10. Also for testing purposes the knife switch 1 is opened to prevent establishment of power connections for the motor M through the medium of contactor 2. With the fuses 7 and 8 inserted in clips 10 the aforedescribed energizing circuits'may be established to test the operation of contactor 2 and rheostat 3, providing the normally open push button switch 13 is held depressed. Contactor 2 always opens immediately upon release of push button 13 and can only be reclosedupon return of rheostat 3 to normal position. Thus provision is made to prevent accidental starting of the controlled motor upon reclosure of knife switch 1 aftertesting operations. In practice the push button switch 13 is-located at some distance from knife switch 1 to prevent the operator from throwing the knife switch 1 to closed position while maintaining switch 13 in closed position.

In connection with the foregoing it should be noted that the invention is not limited to controllers of the character shown in the drawing. For example, the same may be embodied in controllers having electro-mag net-i0 contactors for controlling the starting resistance and may be also used in connection with controllers of the reversing type. However, the invention is particularly aplicable to systems of control such as are commonly used in connection with printing presses employing a rheostat of the character shown in the drawing.

What I claim and desire ters Patent is: i

1. The combination with a controller including an elect-romagnetically operated control element, of testing means therefor including means for interrupting the line connections for said controller, and means including a normally open switch for establishing an energizing circuit for said control element upon interruption of the line connections for said controller'by said former means.

2. The combination with a motor controller including an electromagnetically operated motor controlling element, of means for controlling the line connections for said controller, and testing means for said controller including a normally open switch for establishing an energizing circuit for said element upon interruption of the line connections for said controller by said former means.

3. The combination with a motor controller including a plurality of motor controlling elements, of a switch associated with said controller for controlling the line connections therefor, and testing means for said elements including a testing switch for establishing an energizing circuit for said elements upon opening of said main switch, said testing switch being biased towards open position.

4. The combination with a motor controller including a plurality of electromagnetically' operated motor controlling elements, of a main switch associated with said controller for controlling the line connections therefor and testing means for said controller including means for establishing an energizing circuit forsaid elements upon opening of said main switch and for insuring against response of one of said elements except upon normal positioning of the other pf said elements.

to secure by Let- 5. The combination with a motor controller including an electromagnetically operated main switch and a motor operated rheostat. of a manually operated switch for tablishing an energizing circuit for said main switch and the operating motor for said rheostat upon interruption of the line connections for said'controller by said main switch.

6. The combination with a motor conrheostat, of a manually operated switch for mal positionin troller including an electromagnetically operated main switch and a motor operated controllin the line connections .for said controller an testing means for said controller including a normally open switch for controlling the energizing" circuit of saidmain switch and the operating motor of said rheostat u erated switch, and means insuring against closure of said main switch except upon norof said rheostat.

ination with a motor con- 7. The .com troller, of a swltch for controlling the line connections therefor and means for test said controller upon interruption of sai line connections, said latter means includin a testing switch located at a point remov from the former switch to prevent simuln opening of said manually op-' taneous operation otsaid switches by the operator.

8. The combination with a motor controller including an electromagnetically operated main switch and. a motor operated rheostat,-of a manually operated switch for controlling the line connections for said controller, a pair of fuses to be included in the energizing circuits of said main switch and the operating motor of said rheostat, means for select vely connecting said fuses between said controller and said manually operated switch, or ahead of said manually operated switch, and meansfor normally interrupting the circuitthrough said fuses upon establish- 7 ment of the latter connections.

In witnes whereof, I have hereunto subscribed my name.

EDWIN W. SEEGER. 

